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  • 1
    Online Resource
    Online Resource
    Frontiers Media SA ; 2022
    In:  Frontiers in Medicine Vol. 9 ( 2022-7-19)
    In: Frontiers in Medicine, Frontiers Media SA, Vol. 9 ( 2022-7-19)
    Abstract: Immunoglobulin (Ig) production during and after infection with Plasmodium parasites is one of the greatest adaptive immune defenses the human host has against this parasite. Infection with P. falciparum has been shown to induce different B cell maturation responses dependent upon the age of the patient, number of previous exposures, and severity of the disease. Described here are dynamics of Ig responses to a panel of 32 P. falciparum antigens by patients followed for 42 days and classified individuals as showing characteristics of an apparent first P. falciparum infection (naïve) or a repeat exposure (non-naïve). Six parameters were modeled to characterize the dynamics of IgM, IgG 1 , IgG 3 , and IgA for these two exposure groups with differences assessed among Ig isotypes/subclasses and unique antigens. Naïve patients had significantly longer periods of time to reach peak Ig titer (range 4–7 days longer) and lower maximum Ig titers when compared with non-naïve patients. Modeled time to seronegativity was significantly higher in non-naïve patients for IgM and IgA, but not for the two IgG subclasses. IgG 1 responses to Rh2030, HSP40, and PfAMA1 were at the highest levels for non-naïve participants and may be used to predict previous or nascent exposure by themselves. The analyses presented here demonstrate the differences in the development of the Ig response to P. falciparum if the infection represents a boosting response or a primary exposure. Consistency in Ig isotype/subclasses estimates and specific data for P. falciparum antigens can better guide interpretation of seroepidemiological data among symptomatic persons.
    Type of Medium: Online Resource
    ISSN: 2296-858X
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2022
    detail.hit.zdb_id: 2775999-4
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  • 2
    Online Resource
    Online Resource
    Frontiers Media SA ; 2023
    In:  Frontiers in Medicine Vol. 10 ( 2023-2-17)
    In: Frontiers in Medicine, Frontiers Media SA, Vol. 10 ( 2023-2-17)
    Type of Medium: Online Resource
    ISSN: 2296-858X
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2023
    detail.hit.zdb_id: 2775999-4
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  • 3
    In: Frontiers in Cellular and Infection Microbiology, Frontiers Media SA, Vol. 12 ( 2022-11-8)
    Abstract: IgG serology can be utilized to estimate exposure to Anopheline malaria vectors and the Plasmodium species they transmit. A multiplex bead-based assay simultaneously detected IgG to Anopheles albimanus salivary gland extract (SGE) and four Plasmodium falciparum antigens (CSP, LSA-1, PfAMA1, and PfMSP1) in 11,541 children enrolled at 350 schools across Haiti in 2016. Logistic regression estimated odds of an above-median anti-SGE IgG response adjusting for individual- and environmental-level covariates. Spatial analysis detected statistically significant clusters of schools with students having high anti-SGE IgG levels, and spatial interpolation estimated anti-SGE IgG levels in unsampled locations. Boys had 11% (95% CI: 0.81, 0.98) lower odds of high anti-SGE IgG compared to girls, and children seropositive for PfMSP1 had 53% (95% CI: 1.17, 2.00) higher odds compared to PfMSP1 seronegatives. Compared to the lowest elevation, quartiles 2-4 of higher elevation were associated with successively lower odds (0.81, 0.43, and 0.34, respectively) of high anti-SGE IgG. Seven significant clusters of schools were detected in Haiti, while spatially interpolated results provided a comprehensive picture of anti-SGE IgG levels in the study area. Exposure to malaria vectors by IgG serology with SGE is a proxy to approximate vector biting in children and identify risk factors for vector exposure.
    Type of Medium: Online Resource
    ISSN: 2235-2988
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2022
    detail.hit.zdb_id: 2619676-1
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  • 4
    In: Frontiers in Public Health, Frontiers Media SA, Vol. 10 ( 2022-6-9)
    Abstract: Integrated surveillance for multiple diseases can be an efficient use of resources and advantageous for national public health programs. Detection of IgG antibodies typically indicates previous exposure to a pathogen but can potentially also serve to assess active infection status. Serological multiplex bead assays have recently been developed to simultaneously evaluate exposure to multiple antigenic targets. Haiti is an island nation in the Caribbean region with multiple endemic infectious diseases, many of which have a paucity of data for population-level prevalence or exposure. Methods A nationwide serosurvey occurred in Haiti from December 2014 to February 2015. Filter paper blood samples ( n = 4,438) were collected from participants in 117 locations and assayed for IgG antibodies on a multiplex bead assay containing 15 different antigens from 11 pathogens: Plasmodium falciparum, Toxoplasma gondii , lymphatic filariasis roundworms, Strongyloides stercoralis , chikungunya virus, dengue virus, Chlamydia trachomatis, Treponema pallidum , enterotoxigenic Escherichia coli, Entamoeba histolytica , and Cryptosporidium parvum . Results Different proportions of the Haiti study population were IgG seropositive to the different targets, with antigens from T. gondii, C. parvum , dengue virus, chikungunya virus, and C. trachomatis showing the highest rates of seroprevalence. Antibody responses to T. pallidum and lymphatic filariasis were the lowest, with & lt;5% of all samples IgG seropositive to antigens from these pathogens. Clear trends of increasing seropositivity and IgG levels with age were seen for all antigens except those from chikungunya virus and E. histolytica . Parametric models were able to estimate the rate of seroconversion and IgG acquisition per year for residents of Haiti. Conclusions Multiplex serological assays can provide a wealth of information about population exposure to different infectious diseases. This current Haitian study included IgG targets for arboviral, parasitic, and bacterial infectious diseases representing multiple different modes of host transmission. Some of these infectious diseases had a paucity or complete absence of published serological studies in Haiti. Clear trends of disease burden with respect to age and location in Haiti can be used by national programs and partners for follow-up studies, resource allocation, and intervention planning.
    Type of Medium: Online Resource
    ISSN: 2296-2565
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2022
    detail.hit.zdb_id: 2711781-9
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  • 5
    Online Resource
    Online Resource
    Frontiers Media SA ; 2021
    In:  Frontiers in Immunology Vol. 12 ( 2021-3-2)
    In: Frontiers in Immunology, Frontiers Media SA, Vol. 12 ( 2021-3-2)
    Abstract: Human Plasmodium infection produces a robust adaptive immune response. Time courses for 104 children followed for 42 days after initiation of Plasmodium falciparum chemotherapy were assayed for antibody levels to the five isotypes of human immunoglobulins (Ig) and 4 subclasses of IgG for 32 P. falciparum antigens encompassing all 4 parasite stages of human infection. IgD and IgE against these antigens were undetectable at 1:100 serum concentration, but other Ig isotypes and IgG subclasses were consistently observed against all antigens. Five quantitative parameters were developed to directly compare Ig response among isotypes and antigens: C max , maximum antibody level; Δ C , difference between C max and the antibody level at Day 0; t max , time in days to reach C max ; t 1/2 , Ig signal half-life in days; t neg , estimated number of days until complete loss of Ig signal. Classical Ig patterns for a bloodborne pathogen were seen with IgM showing early t max and IgG production highest among Ig isotypes. However, some unexpected trends were observed such as IgA showing a biphasic pattern for many antigens. Variability among these dynamics of Ig acquisition and loss was noted for different P. falciparum antigens and able to be compared both quantitatively and statistically. This parametrization methodology allows direct comparison of Ig isotypes produced against various Plasmodium antigens following malaria infection, and the same methodology could be applied to other longitudinal serologic studies from P. falciparum or different pathogens. Specifically for P. falciparum seroepidemiological studies, reliable and quantitative estimates regarding the IgG dynamics in human populations can better optimize modeling efforts for serological outputs.
    Type of Medium: Online Resource
    ISSN: 1664-3224
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2021
    detail.hit.zdb_id: 2606827-8
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  • 6
    In: Frontiers in Immunology, Frontiers Media SA, Vol. 14 ( 2023-8-24)
    Abstract: Plasmodium falciparum malaria is a leading cause of child mortality in Nigeria. Neonates are born with maternal antibodies from placental transfer which may protect against malaria infection in the first months of life. The IgG dynamics of the transition from passively transferred antimalarial antibodies to actively acquired IgG from natural exposure have not been well elucidated. Methods Blood samples collected during a 2018 Nigeria nationwide HIV/AIDS household survey were available for 9,443 children under 5 years of age, with a subset of infants under 2 months of age having maternal samples available (n=41). Samples were assayed for the P. falciparum HRP2 antigen and anti-malarial IgG antibodies. LOESS regression examined the dynamics in IgG response in the first 5 years of life. Correlation with maternal IgG levels was assessed for mother/child pairs. Results Consistent decreases were observed in median IgG levels against all Plasmodium spp. antigen targets for the first months of life. At a population level, P. falciparum apical membrane antigen-1 (AMA1) and merozoite surface protein-1 19kD (PfMSP1) IgG decreased during the first 12 months of life before reaching a nadir, whereas IgGs to other targets only declined for the first 4 months of life. Seropositivity showed a similar decline with the lowest seropositivity against AMA1 and PfMSP1 at 10-12 months, though remaining above 50% during the first 2 years of life in higher transmission areas. No protective association was observed between IgG positivity and P. falciparum infection in infants. Maternal antibody levels showed a strong positive correlation with infant antibody levels for all P. falciparum antigens from birth to 2 months of age, but this correlation was lost by 6 months of age. Discussion Maternally transferred anti-malarial IgG antibodies rapidly decline during the first 6 months of life, with variations among specific antigens and malaria transmission intensity. From 3-23 months of age, there was a wide range in IgG levels for the blood-stage antigens indicating high individual variation in antibody production as children are infected with malaria. Non- falciparum species-specific antigens showed similar patterns in waning immunity and correlation with paired mother’s IgG levels compared to P. falciparum antigens.
    Type of Medium: Online Resource
    ISSN: 1664-3224
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2023
    detail.hit.zdb_id: 2606827-8
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  • 7
    In: Frontiers in Immunology, Frontiers Media SA, Vol. 11 ( 2020-5-15)
    Type of Medium: Online Resource
    ISSN: 1664-3224
    Language: Unknown
    Publisher: Frontiers Media SA
    Publication Date: 2020
    detail.hit.zdb_id: 2606827-8
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